/*-
 * Public platform independent Near Field Communication (NFC) library examples
 * 
 * Copyright (C) 2009, Roel Verdult
 * Copyright (C) 2010, Romuald Conty
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *  1) Redistributions of source code must retain the above copyright notice,
 *  this list of conditions and the following disclaimer. 
 *  2 )Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in the
 *  documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Note that this license only applies on the examples, NFC library itself is under LGPL
 *
 */

/** Relay example using two devices. */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <signal.h>

#include <host/nfc.h>

#include "nfc-utils.h"

#define MAX_FRAME_LEN 264
#define MAX_DEVICE_COUNT 2

static byte_t abtReaderRx[MAX_FRAME_LEN];
static byte_t abtReaderRxPar[MAX_FRAME_LEN];
static size_t szReaderRxBits;
static byte_t abtTagRx[MAX_FRAME_LEN];
static byte_t abtTagRxPar[MAX_FRAME_LEN];
static size_t szTagRxBits;
static nfc_device_t *pndReader;
static nfc_device_t *pndTag;
static bool quitting = false;

void intr_hdlr(void)
{
	printf("\nQuitting...\n");
	quitting = true;
	return;
}

void print_usage(char *argv[])
{
	printf("Usage: %s [OPTIONS]\n", argv[0]);
	printf("Options:\n");
	printf("\t-h\tHelp. Print this message.\n");
	printf("\t-q\tQuiet mode. Suppress output of READER and EMULATOR data (improves timing).\n");
}

int main(int argc, char *argv[])
{
	int arg;
	bool quiet_output = false;
	size_t szFound;
	nfc_device_desc_t *pnddDevices;
	const char *acLibnfcVersion = nfc_version();
	nfc_target_t nt;
	nfc_iso14443a_info_t nai = {
		{ 0x04, 0x00 },
		0x20,
		4,
		{ 0x08, 0xad, 0xbe, 0xef },
		0,
	};
	
	/* Get commandline options */
	for (arg = 1; arg < argc; arg++) {
		if (0 == strcmp(argv[arg], "-h")) {
			print_usage(argv);
			return EXIT_SUCCESS;
		} else if (0 == strcmp(argv[arg], "-q")) {
			quiet_output = true;
		} else {
			ERR("%s is not supported option.", argv[arg]);
			print_usage(argv);
			return EXIT_FAILURE;
		}
	}
	
	/* Display libnfc version */
	printf("%s uses libnfc %s\n", argv[0], acLibnfcVersion);
	
#ifdef WIN32
	signal(SIGINT, (void(__cdecl *)(int))intr_hdlr);
#else
	signal(SIGINT, (void (*)(void))intr_hdlr);
#endif
	
	/* Allocate memory to put the result of available devices listing
	 */
	if (!(pnddDevices = malloc(MAX_DEVICE_COUNT * sizeof (*pnddDevices)))) {
		fprintf(stderr, "malloc() failed\n");
		return EXIT_FAILURE;
	}
	/* List available devices */
	nfc_list_devices(pnddDevices, MAX_DEVICE_COUNT, &szFound);
	
	if (szFound < 2) {
		ERR("%zd device found but two connected devices are needed to relay NFC.", szFound);
		return EXIT_FAILURE;
	}
	/* Try to open the NFC emulator device */
	pndTag = nfc_connect(&(pnddDevices[0]));
	if (pndTag == NULL) {
		printf("Error connecting NFC emulator device\n");
		return EXIT_FAILURE;
	}
	
	printf("Hint: tag <---> initiator (relay) <---> target (relay) <---> original reader\n\n");
	
	printf("Connected to the NFC emulator device: %s\n", pndTag->acName);
	printf("[+] Try to break out the auto-emulation, this requires a second reader!\n");
	printf("[+] To do this, please send any command after the anti-collision\n");
	printf("[+] For example, send a RATS command or use the \"nfc-anticol\" tool\n");
	
	nt.nm.nmt = NMT_ISO14443A;
	nt.nm.nbr = NBR_UNDEFINED;
	memcpy(&nt.nti.nai, &nai, sizeof (nai));
	
	if (!nfc_target_init(pndTag, &nt, abtReaderRx, &szReaderRxBits)) {
		ERR("%s", "Initialization of NFC emulator failed");
		nfc_disconnect(pndTag);
		return EXIT_FAILURE;
	}
	printf("%s", "Configuring emulator settings...");
	if (!nfc_configure(pndTag, NDO_HANDLE_CRC, false) ||
	    !nfc_configure(pndTag, NDO_HANDLE_PARITY, false) || !nfc_configure (pndTag, NDO_ACCEPT_INVALID_FRAMES, true)) {
		nfc_perror(pndTag, "nfc_configure");
		exit(EXIT_FAILURE);
	}
	printf("%s", "Done, emulated tag is initialized");
	
	/* Try to open the NFC reader */
	pndReader = nfc_connect(&(pnddDevices[1]));
	
	printf("Connected to the NFC reader device: %s",
	       pndReader->acName);
	printf("%s", "Configuring NFC reader settings...");
	nfc_initiator_init(pndReader);
	if (!nfc_configure(pndReader, NDO_HANDLE_CRC, false) ||
	    !nfc_configure(pndReader, NDO_HANDLE_PARITY, false) ||
	    !nfc_configure(pndReader, NDO_ACCEPT_INVALID_FRAMES, true)) {
		nfc_perror(pndReader, "nfc_configure");
		exit(EXIT_FAILURE);
	}
	printf("%s", "Done, relaying frames now!");
	
	while (!quitting) {
		/* Test if we received a frame from the reader */
		if (nfc_target_receive_bits(pndTag, abtReaderRx,
					    &szReaderRxBits,
					    abtReaderRxPar)) {
			/* Drop down the field before sending a REQA
			 * command and start a new session
			 */
			if (szReaderRxBits == 7 && abtReaderRx[0] == 0x26) {
				/* Drop down field for a very short time
				 * (original tag will reboot)
				 */
				if (!nfc_configure(pndReader, NDO_ACTIVATE_FIELD, false)) {
					nfc_perror(pndReader, "nfc_configure");
					exit(EXIT_FAILURE);
				}
				if (!quiet_output)
					printf("\n");
				if (!nfc_configure(pndReader, NDO_ACTIVATE_FIELD, true)) {
					nfc_perror(pndReader, "nfc_configure");
					exit(EXIT_FAILURE);
				}
			}
			/* Print the reader frame to the screen */
			if (!quiet_output) {
				printf("R: ");
				print_hex_par(abtReaderRx, szReaderRxBits, abtReaderRxPar);
			}
			/* Forward the frame to the original tag */
			if (nfc_initiator_transceive_bits(pndReader,
							  abtReaderRx,
							  szReaderRxBits,
							  abtReaderRxPar,
							  abtTagRx,
							  &szTagRxBits,
							  abtTagRxPar)) {
				/* Redirect the answer back to the reader */
				if (!nfc_target_send_bits(pndTag,
							  abtTagRx,
							  szTagRxBits,
							  abtTagRxPar)) {
					nfc_perror(pndTag,
						   "nfc_target_send_bits");
					exit(EXIT_FAILURE);
				}
				/* Print the tag frame to the screen */
				if (!quiet_output) {
					printf("T: ");
					print_hex_par(abtTagRx, szTagRxBits, abtTagRxPar);
				}
			}
		}
	}
	
	nfc_disconnect(pndTag);
	nfc_disconnect(pndReader);
	exit(EXIT_SUCCESS);
}
